The present invention involves the diagnosis of bladder cancer comprising detection of a particular and unique proteinaceous urine component.
Bladder cancer consists of a heterogenous group of tumors with varied capacities for invasion and metastasis. This disease accounts for 2 per cent of all malignancies and is the 5th most prevalent cancer among adults in the United States..sup.1 In the effort to identify biochemical markers that may have diagnostic and prognostic value, various noninvasive tests have been developed, including tests to identify tumor-associated markers in the urine, serum, and bladder cancer tissue specimens. Among the various tumor-associated markers studied, urinary immunoglobulins have been found to increase in persons who have bladder cancer.sup.2-7 and appear to have some diagnostic and prognostic value..sup.8-10 There are no data, however, to indicate that these antibodies are specifically directed toward bladder carcinoma antigens.
In an earlier communication.sup.11 the present inventors demonstrated that, in comparison to normal controls, the immunoglobulin G heavy- and light-chain fractions appear to be enriched in the urine samples of persons with bladder cancer. The urine of patients with bladder cancer has long been subject to scrutiny as a possible source of either a diagnostic or a prognostic tumor marker. Since urine comes in direct contact with and bathes bladder neoplasms and is known to contain immunoglobulins, .sup.2,6 antigens,.sup.22,23 exfoliated tumor cells,.sup.24 and other proteins,.sup.6,10 it continues to be the medium of greatest interest in the search for a common tumor-associated protein. Although one of the present inventors has previously reported on the apparent relationship of urinary immune complexes to the stage of disease, no specific bladder cancer-associated antigen in immune complex has been identified..sup.18